Two sources of fire risks - skyscraper-dense cities, and villages with limited access to firefighting equipment - are priorities in China's fire-control campaign, according to a senior official, and more rigorous investigations will be undertaken by local governments when fires result in injuries or fatalities.

Yu Jianhua, director of the firefighting department of the Ministry of Public Security, said at a news briefing on Friday that more investigations with stricter standards will be conducted in cases of fires that have casualties.

The State Council will organize investigations into fires that cause more than 30 deaths, Yu said, while provincial-level governments must investigate one that kills more than 10 people but less than 30. City governments are responsible for investigating when there are four to nine deaths, and county governments must handle cases with up to three fatalities.

The rule came with a new work plan for fire control that was released by the State Council on Thursday. It aims to prevent large-scale fires nationwide. The notice pointed to the heads of local governments as first in the line of responsibility for fire fatalities.

Yu said the plan clarifies the responsibilities of each level of government. Those in charge of fire control will face penalties if they fail to fulfill their duty, the work plan said.

The biggest risk of fire arises in well-developed cities and in rural areas with less equipment, he said.

China is conducting fire control checks of skyscrapers nationwide, bringing more than 610,000 tall buildings under scrutiny, Yu said.

According to the ministry, China ranks first in the world in number of tall buildings, and more than 6,000 of them are higher than 100 meters. The tallest building, in Shanghai, rises more than 600 meters.

"Last year, I visited London, which has about 500 tall buildings. By comparison, Beijing alone has more than 25,000. The large number has led to fire control risks," he said.

Meanwhile, 24.7 million square meters of underground spaces in more than 20 provinces and municipalities also face risks, Yu said, as some of these spaces have been altered into hostels or apartments for rent. They're dangerous, he said.

The country also has more than 10,000 large shopping complexes of more than 10,000 square meters, more than 100,000 shantytowns in downtown areas of cities and more than 100,000 chemical companies, he added.